Abstract: As cloud computing becomes popular, more and more sensitive information are being centralized into the cloud nowadays. For the protection of data privacy, sensitive data usually have to be encrypted before outsourcing, which makes effective data utilization a very challenging task because all the data which we outsource are in encrypted format. In this paper, we have discussed a few approaches for sharing data on cloud with minimal usage of key. We also discuss few data searching technique over encrypted data. While enjoying the advantage and convenience of cloud storage for data sharing, users are becoming more worried about careless leak of data in the cloud. To address this problem we studied various leakage models.
Keywords: Auxiliary Input, Key Aggregate, Leakage Resilient, Searchable.